1. Field of the Invention
The present invention relates to instrumentation using the medullary canal of a tibia to accurately position means for preparing a tibial plateau with a posterior slope.
2. Information Disclosure Statement
Various instrumentation and methods have been heretofore developed for preparing the proximal end of a tibia to receive a proximal tibial prosthesis. Whiteside, U.S. Pat. No. 4,467,801, issued Aug. 28, 1984, discloses instrumentation and methods which uses the long central axis of a tibia as a guide in preparing the proximal end of the tibia to receive a proximal tibia prosthesis. The Whiteside U.S. Pat. No. 4,467,801 teaches shaping of the proximal tibial surface by first using an oscillating saw to resect a small amount of the superior proximal surface to form an approximately planar surface. A combination reamer/alignment guide is then advanced through the approximate location on the superior proxima surface of the tibia which corresponds to the central long axis of the tibia to form an intramedullary hole or bore down the center of the tibial shaft into the medullary canal of the tibia. The reamer/alignment guide has a longitudinal axis that will be aligned with the longitudinal or long axis of the tibia shaft once the reamer/alignment guide is fully inserted into the tibia. After the reamer/alignment guide is fully inserted into the tibia, a plateau planer is attached to the upper end thereof in such a manner that the cutting surfaces of the planer is transverse to the longitudinal axis of the reamer/alignment guide and, therefore, to the longitudinal or long axis of the tibia.
Nothing in the known prior art discloses or suggests the present invention. More specifically, nothing in the known prior art discloses or suggests instrumentation or a method including an intramedullary alignment guide for engaging the tibia, and a rotational alignment guide means for guiding the insertion of a rod portion of the intramedullary alignment guide into an intramedullary bore in the tibia with the intramedullary alignment guide rotationally aligned with the intramedullary bore so that the longitudinal axis of a handle portion of the intramedullary alignment guide is angled posteriorly with respect to the longitudinal axis of the rod portion and the longitudinal axis of the intramedullary bore as the rod portion of the intramedullary alignment guide is inserted into the intramedullary bore.